Plastic-bonded pyrotechnical mixture for producing alkali metal chloride or earth alkali metal chloride aerosols as smokescreen

ABSTRACT

A plastic-bonded pyrotechnical mixture is provided that includes at least one oxidatizer, one carbonate and/or phosphate from the group of alkali metals or earth alkali metals, a chlorinated rubber and a softener. An additional bonding agent and/or graphite can be added thereto as needed. The oxidatizer can be a perchlorate or a mixture of perchlorates from the group of alkali metals or earth alkali metals, or alternatively, ammonium perchlorates can also be integrated as an oxidatizer. The softener is an organic substance or substance mixture from the group of adipates or phthalates, or can be an organic phosphoric acid ester or a phosphoric acid ester mixture. As an additional bonding agent, an organic titanate or an organic titanate mixture is preferred. All components are mixed with one another at such a ratio that a neutral smoke in the pH range of 5-7 (bases on aerosol) is created.

This nonprovisional application is a continuation of InternationalApplication No. PCT/EP2010/005664, which was filed on Sep. 15, 2010, andwhich claims priority to German Patent Application No. DE 10 2009 049003, which was filed in Germany on Oct. 9, 2009, and which are bothherein incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to the generation and release of alkalimetal chloride and alkaline earth metal chloride aerosols withsmokescreen effect through the reaction of plastic-bound activepyrotechnic compositions, especially in the context of smoke grenades.

2. Description of the Background Art

Pyrotechnic mixtures for generating inorganic aerosols for militaryscreening purposes often contain toxicologically objectionablesubstances. For simulation and training purposes, therefore, it ispreferred to employ practice systems which release aerosols that are oflow toxicity and are as far as possible pH-neutral (pH 5-7).

In the case of practice systems for smoke hand grenades, moreover, arequirement is that for a effective training they should not onlygenerate a smoke of low toxicity but also should have the geometry andmass of the corresponding deployment versions.

In the case of grenades which generate a spontaneous smoke, the activepyrotechnic smoke composition is ignited by a break-up charge anddelivered. A corresponding rapid smoke hand grenade based on apyrotechnic charge which comprises red phosphorus is published in theform of DE 195 48 436 C1, which corresponds to U.S. Pat. No. 5,700,971.

For practice systems, in the case of the above-recited rapid smokegrenades, the active pyrotechnic compositions can be switched relativelyeasily for finely ground inorganic substance/mineral mixtures, which arethen delivered via the break-up charge. For realistic training, in thearea of the rapid smoke hand grenades, the compositions of therespective applications can be simulated well via the bulk density ofthe powderous substance/mineral mixtures and/or their compression in theprevailing volume.

In the case of nonspontaneous smoke grenades that generate condensationaerosols, the inorganic substances with smokescreen effect are generatedfrom the active pyrotechnic composition present, after ignition. Onesuch active pyrotechnic composition is published in the form, forexample, of DE 27 43 363, which corresponds to U.S. Pat. No. 4,376,001.

For practice systems of the above-described smoke grenades whichgenerate nonspontaneous condensation aerosols, pyrotechnic colored smokecharges or pyrotechnic charges with heating beds containing metal powderare used for expelling, for example, alkali metal chlorides, see DE 102008 010 942, which corresponds to US 20090211672, which is incorporatedherein by reference. A problem which arises here in the area of handgrenades is that with the corresponding application systems it ispossible to produce effective simulation only of those smoke handgrenades that have masses of more than 300 g.

With colored smoke devices or application systems in which, for example,alkali metal chlorides are expelled via heating beds containing metalpowder, the specific construction means that the aerosols are blown outonly in one direction, and this can lead to reduced output by theapplication systems under diverse climatic and geographical conditions;for example, the blowing-out of the aerosol in snow causes it tocondense rapidly, resulting in a reduced smoke output.

The burning characteristics of active pyrotechnic smoke compositionswhich generate the inorganic substances that, in conjunction withatmospheric moisture, are effective as smoke, and do so only throughreaction of these inorganic substances in the form of condensationaerosols, can be simulated only to a limited degree by applicationsystems which utilize pyrotechnic heating beds for the sublimation oforganic substances (colored smoke) or inorganic substances (e.g., alkalimetal chlorides).

DETAILED DESCRIPTION OF THE INVENTION

The idea on which an embodiment of the invention is based, in analogy tothe known condensation aerosol mist-generating active pyrotechniccompositions, is that of using a plastic-bound pyrotechnic mixture withwhich alkali metal chloride and/or alkaline earth metal chlorideaerosols, which are of comparatively low toxicity and produce asmokescreen effect, are generated in situ by reaction. In addition tothe corresponding perchlorates as a source of alkali metal chlorideand/or alkaline earth metal chloride, the reaction of the proposedpyrotechnic mixtures comprising the chlorinated rubber present inconjunction with the alkali metal and/or alkaline earth metal carbonatesand/or phosphates present additionally generates the correspondingalkali metal and/or alkaline earth metal chloride. All of the componentsare blended in a proportion to one another such that a neutral smoke inthe range of pH 5-7 (based on aerosol) is formed.

A smoke charge having the above features of the invention contains forexample: 56.7% by weight potassium perchlorate; 19.8% by weightpotassium carbonate; 15.0% by weight polychloroisoprene; and/or 8.5% byweight plasticizer

In a development of the invention, the smoke effect of the activecompositions can be enhanced by admixing ammonium perchlorate with thecorrespondingly required amounts of alkali metal and/or alkaline earthmetal carbonates and/or phosphates. This effect is based on theadditional release of steam, which promotes smoke condensation. In thisway it is possible to respond to customer requirements with regard,among other things, to smoke performance, toxicity, and pH-neutrality ofthe aerosol, in a simple way.

A smoke charge in a development of the invention contains for example:50.6% by weight potassium perchlorate; 11.6% by weight ammoniumperchlorate; 14.3% by weight lithium carbonate; 15.0% by weightpolychloroisoprene; and/or 8.5% by weight plasticizer

The heat released on the reaction of the active pyrotechnic compositionserves for the sublimation of the aerosol-active alkali metal and/oralkaline earth metal chlorides.

The plastic-bound pyrotechnic mixture therefore, in accordance with theinvention, comprises at least one oxidizer, a carbonate and/or phosphateand/or a mixture of carbonates and/or phosphates from the group of thealkali metals and/or alkaline earth metals, a chlorinated rubber, and aplasticizer. Added thereto, optionally, may be a further binder and/orgraphite. The oxidizer ought preferably to be a perchlorate or a mixtureof perchlorates from the group of the alkali metals and/or alkalineearth metals. Additionally or alternatively, ammonium perchlorate can beincorporated as an oxidizer. The plasticizer, in contrast, is preferablyan organic substance or a substance mixture from the group of theadipates, citrates or phthalates. Alternatively the plasticizer may bean organic phosphoric ester or a phosphoric ester mixture. An additionalbinder used with preference is an organic titanate or an organictitanate mixture.

Consequently, a plastic-bonded active pyrotechnic composition isproposed which through a variation in its constitution is suitable forgenerating smokescreens, going as far as smokescreens of low toxicityfor practice purposes. The plastic-bound active pyrotechnic composition,like other active smoke compositions, can be employed as well ingrenades/munitions, hand grenades or fixed application systems.

The proposed plastic-bound active composition is especially suitable foruse as a caseless element, thus allowing, among other things, handgrenades having masses of up to 300 g to be made available, and incomparison to colored smoke application systems, for example, saidgrenades being more powerful.

Caseless hand grenades based on the proposed plastic-bound pyrotechnicmixtures are equal in terms of geometry, mass, burning characteristics,and burning time, virtually, to the corresponding, likewiseplastic-bound, NT active smoke composition application system, whoseactive smoke component is zinc chloride or complexed zinc chloride(NT-Nebel, see http:/www.brandschutz-passin.de/download/Merkblatt NTNebelkörper.pdf). This allows realistic training with a reduction inpotential toxicity at the same time—in other words, in conjunction withthe NT active smoke composition, the plastic-bound active compositionsproposed allow the provision of a deployment and practice system forsmoke hand grenades that is complete in respect of handling, etc.

The invention being thus described, it will be obvious that the same maybe varied in many ways. Such variations are not to be regarded as adeparture from the spirit and scope of the invention, and all suchmodifications as would be obvious to one skilled in the art are to beincluded within the scope of the following claims.

1. A plastic-bound pyrotechnic mixture comprising at least one oxidizer,a carbonate and/or phosphate or a mixture of carbonates and/orphosphates from the group of the alkali metals and/or alkaline earthmetals, a chlorinated rubber, and a plasticizer.
 2. The plastic-boundpyrotechnic mixture of claim 1, wherein all of the components areblended in a ratio to one another such that a neutral smoke in the rangepH 5-7,relative to the aerosol is formed.
 3. The plastic-boundpyrotechnic mixture of claim 1, wherein a further binder and/or agraphite is incorporated.
 4. The plastic-bound pyrotechnic mixture ofclaim 1, wherein the oxidizer is a perchlorate or a mixture ofperchlorates from the group of the alkali metals and/or alkaline earthmetals.
 5. The plastic-bound pyrotechnic mixture of claim 1, wherein,alternatively or additionally, ammonium perchlorate is incorporated asthe oxidizer.
 6. The plastic-bound pyrotechnic mixture of claim 1,wherein the plasticizer is an organic substance or substance mixturefrom the group of the adipates, citrates or phthalates.
 7. Theplastic-bound pyrotechnic mixture of claim 1, wherein the plasticizer isan organic phosphoric ester or a phosphoric ester mixture.
 8. Theplastic-bound pyrotechnic mixture of claim 2, wherein the additionalbinder is an organic titanate or an organic titanate mixture. 9.Caseless and encased smoke grenades or munitions, smoke hand grenades,and fixed smoke application systems, wherein a plastic-bound pyrotechnicmixture according to claim 1 is incorporated therein.